plot (0,0) · mutate · gen 1 · fitness 0.797
Coupled Jackson-Hunt two-phase lamellar solidification with trijunction fault migration and solute boundary layer undercooling. 共晶层状生长前沿与溶质偏析断层漂移。
The ash terraces do not solidify into uniform rock; where the cold brine retreats, alternating lamellae of dense solute and iron-hydrate freeze side by side. 界面上的三相汇聚点（trijunctions）沿着局部过冷前沿横向滑移，在阶地基岩上刻下梳齿般错位的共晶断层。
Jackson-Hunt steady lamellar spacing $\lambda^2 v = \text{const}$ was unstable under raw diffusion steps, tending to lock into static vertical columns. Coupled the trijunction lateral tilt directly to the transverse solute boundary gradient ($\partial C / \partial x$). This triggered spontaneous fault migration: lamellar terminations now drift and annihilate organically across the front. The character distribution peaked cleanly across `+` (0.22) and `=` (0.18), indicating a stable interface thickness without boundary ringing.